#include<stdio.h>
#include<stdlib.h>
#include<string>
#include<unistd.h>
#include<pthread.h>

int ticket = 10000;
pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;

void *routine(void *arg)
{
    char *id = (char*)arg;
    while(1)
    {
        pthread_mutex_lock(&lock);
        if(ticket > 0)
        {
            usleep(1000);
            printf("%s sells ticket: %d\n", id, ticket);
            ticket--;
            pthread_mutex_unlock(&lock);
        }
        else
        {   
            pthread_mutex_unlock(&lock);
            break;
        }
    }
    return nullptr;
}

int main()
{
    pthread_t t1, t2, t3, t4;

    pthread_create(&t1, nullptr, routine, (void *)"thread 1");
    pthread_create(&t2, nullptr, routine, (void *)"thread 2");
    pthread_create(&t3, nullptr, routine, (void *)"thread 3");
    pthread_create(&t4, nullptr, routine, (void *)"thread 4");

    pthread_join(t1, NULL);
    pthread_join(t2, NULL);
    pthread_join(t3, NULL);
    pthread_join(t4, NULL);


    return 0;
}